The X6-1 xmatrix array transducer allows a completely new approach to the diagnostic ultrasound: it permits visualization of fetal heart in real time, without the need for gating, and it is unaffected by motion artefacts. It is obtained in real time, without any spatial reconstruction. The authors compared this technology with the traditional one in two case reports: a diagnostic doubt of small muscular ventricular septal defect was solved using this new technique; a diagnosis of complete atrioventricular septal defect was confirmed. Three-dimensional real-time imaging would seem very precise in the study of fetal heart: the defects were fully visualized from any angulations. This new technology is promising but from the authors’ limited experience, there is no evidence to use it in routine practice. It should be very useful to commence a prospective study on fetuses at risk while testing the superiority of this technique.